ecgsweep
Free ECG simulator

Every wave, measured.

41 rhythms traced live on calibrated paper at 25 mm/s, a 12-lead that shows conduction blocks and electrolytes, and flashcards to test yourself. Learn from a moving trace, not a frozen picture.

Open the simulatorTest yourself →
Normal Sinus Rhythm
HR72

Tap a rhythm to switch the live trace.

Open in the simulator →

Showing Normal Sinus Rhythm in lead II.

What's here

Four ways to learn the ECG.

Simulator

41 rhythms

Watch a rhythm trace live on calibrated paper, then read its article.

Open

12-lead

7 conditions

Bundle branch and fascicular blocks, and potassium from peaked T waves to the sine wave.

Open

Axis

3 methods

Turn the axis around the hexaxial dial and watch the six limb leads follow.

Open
V1V6

Flashcards

1 card

A strip, a question and four answers. See your pick marked, then turn the card.

Open

How you learn

Read it yourself, then check your answer.

Each article includes a strip drawn by the simulator. Work through it first: find the P waves, measure the PR intervals, look for the pattern.

Then show the same strip marked up, with every interval measured off the trace itself.

Read the Mobitz I article →
30 seconds of Mobitz I second-degree AV block in lead II: sinus P waves at a steady 72 per minute, with the PR interval lengthening over three beats until a P wave is not conducted, giving grouped beating with a pause after every third QRS.
Mobitz I (Wenckebach) block in lead II. Find the groups, then measure the PR of each beat in one of them.

Test yourself

One strip, four answers.

The newest card from the deck. Pick an answer and see it marked, then turn the card for the findings and the look-alikes.

For educators

Teach with it, in your own course.

Educators at three universities already link to ECG Sweep from their course pages. Everything here is free to use in teaching.

  • Embed it live. Put the running simulator on a course page or in slides with one line of HTML.

  • Link any rhythm. Every rhythm and 12-lead condition has a stable page of its own.

  • Download a strip. Save the current trace as a PNG for handouts, quizzes and exams.

  • Share for teaching. Images can be reused for teaching with attribution, under CC BY-NC-ND 4.0.

See how embedding works
Embed code
<iframe
  src="https://www.ecgsweep.com/embed/simulator/atrial-fibrillation"
  width="640" height="360" loading="lazy"
  title="Atrial fibrillation, ECG by ECG Sweep"></iframe>

Accurate by construction

  • One vector, every lead

    The limb leads are projections of a single heart vector, so leads I, II and III always obey Einthoven's law.

  • Numbers from the strip

    Every interval an article quotes is measured off the strip the simulator draws, and a test fails if they drift apart.

  • Checked against the textbook

    The normal 12-lead is tested against textbook criteria, and every condition against a saved reference.

For education only. ECG Sweep is a teaching tool, not a medical device.

What's next

You choose what we build.

Missing a rhythm, a variant or a 12-lead pattern? The roadmap is what people ask for.

Opens X with your request filled in; you post it from your own account. It tags @ecgsweep.

Questions

Frequently asked.